Off-highway machines, such as, for example, loaders, are typically used to transport a payload material, such as, for example, rock, sand, dirt, or gravel, from one location to another. According to a particular work cycle, the loader may use a work tool, such as a bucket, to capture a portion of the payload material and transfer the captured portion of material to another location. Alternatively, a work cycle may include use of the loader to fill a larger payload capacity machine, such as a haulage truck, which is used to transport the material. According to these work cycles and others, it may be desirable to calculate the weight, or mass, of the payload material that is moved within or transported from a work site. This payload weight or mass calculation may be used to evaluate efficiency, productivity, and profitability of the work site operations.
A variety of onboard payload weight measurement systems exist for calculating or measuring the weight or mass of payload material in a loaded work tool. For example, one system, as disclosed in U.S. Pat. No. 4,635,739 to Foley et. al., uses strut pressure as an indication of payload mass. In particular, the disclosed system includes an electronic controller that monitors strut pressures, compensates for various inaccuracies introduced by load distribution and vehicle attitude, and correlates this information into an actual payload mass. As should be appreciated, this payload information allows the machine to be operated efficiently near a desired capacity without causing undue wear of machine components.
U.S. Patent Application Publication No. 2008/0005938 to Aebischer et al. discloses an apparatus for determining the load of an excavator bucket. In particular, the Aebischer et al. reference teaches the use of a distance-measuring camera supported by a boom of the excavator for measuring distances from the camera to at least three points on the excavator bucket. These measured distances, including a distance to the surface of the load, are used to determine a volume of the bucket load. Although volume information may also be useful in evaluating performance and productivity at a work site, the use of additional equipment, including a distance-measuring camera, may be undesirable.
The present disclosure is directed to one or more of the problems or issues set forth above.